Polymer particles

ABSTRACT

Described are polymers and methods of forming and using same.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. Ser. No. 15/719,197, filed Sep.28, 2017, which claims the benefit of U.S. provisional patentapplication No. 62/401,091, filed Sep. 28, 2016 and U.S. provisionalpatent application No. 62/428,990, filed Dec. 1, 2016, the entiredisclosures each of which is incorporated herein by reference.

FIELD

Described herein are polymeric particles configured for intravasculardelivery of pharmaceutical agents, e.g., to a diseased site. Preparationof these polymer particles is also described.

SUMMARY

Described herein are polymer particles. In some embodiments, theparticles are hydrogel particles. These particles can be configured todeliver pharmaceutical agents and can also be used for embolization. Insome embodiments, the polymers used herein can include at least onemonomer amenable to polymerization, at least one crosslinker, and atleast one pharmaceutical agent chemically bonded to the particle with ahydrolytically degradable linkage. In some embodiments, thepharmaceutical agent can be a polymerizable pharmaceutical agent. As thehydrolytic linkage is broken, the pharmaceutical agent can becontrollably released from the polymer particle.

In some embodiments, the polymer particle can be biostable. In someembodiments, the hydrogel particle can be biostable. In otherembodiments, the crosslinker can be biostable. In other embodiments, theparticle can be biodegradable and/or the crosslinker can bebiodegradable.

In one embodiment, the polymerizable pharmaceutical agent can have astructure

In another embodiment, the polymerizable pharmaceutical agent can have astructure

In another embodiment, the polymerizable pharmaceutical agent can have astructure

In another embodiment, the polymerizable pharmaceutical agent can have astructure

In another embodiment, the polymerizable pharmaceutical agent can have astructure

In another embodiment, the polymerizable pharmaceutical agent can have astructure

In another embodiment, the polymerizable pharmaceutical agent can have astructure

In another embodiment, the polymerizable pharmaceutical agent can have astructure

Methods are also described for forming polymer particles describedherein. In some embodiments, methods can include reacting a prepolymersolution including the components included in the particle, such as butnot limited to, at least one monomer amenable to polymerization, atleast one crosslinker, and at least one pharmaceutical agent.

Also, described herein are methods for treating a vessel. The methodscan include administering to the vessel a plurality of polymer particlesas described herein. In other embodiments, the methods can includeadministering to the vessel a plurality of hydrogel particles asdescribed herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates the kinetics of SN-38 elution from the preloadedparticles.

FIG. 2 illustrates the systemic concentration of SN-38 in plasma overtime.

FIG. 3 illustrates the systemic concentration of oxalipatin in plasmaover time.

DETAILED DESCRIPTION

Described herein are polymeric or polymer particles. In someembodiments, the polymers are hydrogel particles. These particles caninclude a pharmaceutical agent that can be degradably attached to theparticle. In some embodiments, this degradability can be through ahydrolytic, oxidative, or reductive linkage.

In some embodiments, the particles can comprise (i) at least one monomeramenable to polymerization, (ii) at least one crosslinker, and (iii) atleast one polymerizable pharmaceutical agent.

In some embodiments, the monomer(s) and crosslinker(s) provide thephysical properties of the particles. Desired physical properties caninclude elasticity and/or robustness to permit delivery through amicrocatheter or catheter. The polymerizable pharmaceutical agent(s) canpermit the controlled release of the pharmaceutical agent(s) from theparticle.

Monomers generally are low molecular weight chemicals containing asingle polymerizable group. The main functions of the monomers, ifpresent, are to aid the polymerization of the hydrogel and to impartspecific mechanical properties to the resulting hydrogel. The monomerscan be any molecule with a single functionality to incorporate into theresulting hydrogel. In some embodiments, the monomers can include astructure conducive to a desired mechanical property.

Monomers can include acrylamide and/or acrylate monomers. Acrylamidemonomers can include alkylacrylamide monomers. Acrylate monomers caninclude alkylacrylate monomers. Alkyl may be linear alkyl, branchedalkyl, cycloalkyl, or a combination thereof, and in some embodiments,may contain from one to thirty-five carbon atoms. In some embodiments,the alkyl group can include a substituent such as a hydroxyl or glycerolgroup. Other types of acrylamide and acrylate monomers are alsopossible. In some embodiments, monomers can include acrylamide,methacrylamide, dimethyl acrylamide, glycerol monomethacrylate,hydroxypropyl acrylate, methyl methacrylate, combinations thereof, andderivatives thereof.

Monomer concentrations can range from about 5% w/w to about 50% w/w,about 10% w/w to about 50% w/w, about 5% w/w to about 40% w/w, about 10%w/w to about 50% w/w, about 20% w/w to about 50% w/w, about 20% w/w toabout 40% w/w, or about 20% w/w to about 30% w/w of a prepolymersolution used to form the polymer.

In other embodiments, monomer concentrations can range from about 5% w/wto about 50% w/w, about 10% w/w to about 50% w/w, about 5% w/w to about40% w/w, about 10% w/w to about 50% w/w, about 20% w/w to about 50% w/w,about 20% w/w to about 40% w/w, or about 20% w/w to about 30% w/w of adried particle.

Crosslinkers, low molecular weight molecules with a plurality ofpolymerizable moieties, can also be optionally included to impartfurther cross-linking of the resulting particle. The crosslinker can beany molecule with at least two functionalities to incorporate into theresulting hydrogel. The crosslinkers can include a structure conduciveto a desired mechanical property of the particle. Crosslinkers caninclude N,N′-methylenebisacrylamide, ethylene glycol dimethacrylate, orcombinations thereof.

Further or alternatively, biodegradable crosslinkers can be utilized toallow for the particles to dissolve in vivo. Biodegradable crosslinkerscan include esters, carbonates, oxalates, carbamates, thioesters, andcombinations thereof. Crosslinker concentrations can be less than 50% ofthe moles of the prepolymer solution used to form the particles.

In some embodiments, a crosslinker can have a structure

A polymerizable pharmaceutical agent can include a desiredpharmaceutical agent chemically modified to permit incorporation into aparticle polymer network and to permit decoupling from the particle in acontrolled rate at a diseased site. The incorporation can be achieved byadding a moiety amenable to the polymerization mechanism selected forthe particle. The modification can turn the pharmaceutical agent into amonomer. The decoupling can be achieved by adding a linkage unstable ina physiological environment between the polymerization group and thepharmaceutical agent. This linkage can break via hydrolytic, oxidative,or reductive mechanisms available in the physiological environment.

A polymerizable pharmaceutical agent can be a polymerizable variant ofan anticancer drug, an anti-inflammatory drug, an anti-thrombotic drug,an anti-proliferative drug, a derivative thereof, or the like.

In one embodiment, the polymerizable pharmaceutical agent can be ananticancer drug.

In one embodiment, the polymerizable pharmaceutical agent can be apolymerizable derivative of oxaliplatin.

In another embodiment, the polymerizable pharmaceutical agent can be anoxaliplatin polymerizable derivative having a structure

In another embodiment, the polymerizable pharmaceutical agent can be anoxaliplatin polymerizable derivative having a structure

wherein n is 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12;

p is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12; R is O or NH; and R′ is Hor CH₃.

In one embodiment, the polymerizable pharmaceutical agent can be anoxaliplatin polymerizable derivative having a structure

In another embodiment, the polymerizable pharmaceutical agent can be anoxaliplatin polymerizable derivative having a structure

In another embodiment, the polymerizable pharmaceutical agent can be anoxaliplatin polymerizable derivative having a structure

In another embodiment, the polymerizable pharmaceutical agent can be apolymerizable derivative of SN-38 (7-ethyl-10-hydroxy-camptothecin).

In another embodiment, the polymerizable pharmaceutical agent can be aSN-38 polymerizable derivative having a structure

In some embodiments, the polymerizable pharmaceutical agent can be(S)-2-((4,11-diethyl-9-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-4-yl)oxy)-2-oxoethylmethacrylate.

In another embodiment, the polymerizable pharmaceutical agent can be aSN-38 polymerizable derivative having a structure

wherein q is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12; X is O or NH; andX′ is H or CH₃.

In one embodiment, the polymerizable pharmaceutical agent can be a SN-38polymerizable derivative having a structure

In another embodiment, the polymerizable pharmaceutical agent can be aSN-38 polymerizable derivative having a structure

In another embodiment, the polymerizable pharmaceutical agent can be aSN-38 polymerizable derivative having a structure

In some embodiments, the polymerizable pharmaceutical agent can be(S)-2-((((4,11-diethyl-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3′,4′:6,7]indolizino[1,2-b]quinolin-9-yl)oxy)carbonyl)amino)ethylmethacrylate.

Linkages susceptible to breakage in a physiological environment includethose susceptible to hydrolysis, including esters, thioesters,carbamates, oxalates, and carbonates, and those susceptible to enzymaticaction, including peptides that are cleaved by matrixmetalloproteinases, collagenases, elastases, and cathepsins. Multipledecoupling linkages can be utilized to control the rate of release ofthe pharmaceutical agent in a manner that is not possible with only one,i.e. one linkage to permit a large, rapid release immediately followingimplantation and another linkage to permit a slow, sustained releaseover longer periods of time.

After particle preparation with incorporated pharmaceutical agents,extensive washing of the particles can be performed without prematurelyreleasing the pharmaceutical agent. Once the particle is delivered tothe diseased site, the pharmaceutical agent can decouple from theparticle as the linkage breaks.

In some embodiments, to permit polymerization of themonomers/crosslinkers/polymerizable pharmaceutical agent, all thecomponents of the particle have moieties conducive to a polymerizationreaction. In some embodiments, a polymerization mechanism used is freeradical polymerization. If free radical polymerization is utilized toprepare the particles, all components can have ethylenically unsaturatedmoieties. Functionalities for free radical polymerization includeacrylates, methacrylates, vinyl groups, and derivatives thereof.Alternatively, other reactive chemistries can be employed to polymerizethe hydrogel, i.e. nucleophile/N-hydroxysuccinimide esters, vinylsulfone/acrylate, thiol-ene, or maleimide/acrylate. In some embodiments,functional groups of the monomers/crosslinkers/polymerizablepharmaceutical agents can be acrylates and methacrylates.

In other embodiments, if desired, the particle can be designed todissolve in vivo, or biodegrade. Linkages unstable in the physiologicalenvironment can be introduced to the macromer or crosslinker to impartbiodegradation by hydrolytic, oxidative, or reductive mechanisms.Linkages susceptible to breakage in a physiological environment includethose susceptible to hydrolysis, including esters, thioesters,carbamates, oxalates, and carbonates, and those susceptible to enzymaticaction, including peptides that are cleaved by matrixmetalloproteinases, collagenases, elastases, and cathepsins. Multiplecrosslinkers can be utilized to control the rate of degradation in amanner that is not possible with only one.

Visualization of particles may be desired using medically relevantimaging techniques such as fluoroscopy, computed tomography, or magneticresonant imaging to permit intravascular delivery and follow-up.Visualization of the particles under fluoroscopy can be imparted by theincorporation of solid particles of radiopaque materials such as barium,bismuth, tantalum, platinum, gold, and other dense metals into theparticles or by the incorporation of iodine-containing moleculespolymerized into the particle structure.

Visualization agents for fluoroscopy can include barium sulfate andiodine-containing molecules. Visualization of the particles undercomputed tomography imaging can be imparted by incorporation of solidparticles of barium or bismuth or by the incorporation ofiodine-containing molecules polymerized into the particle structure.

Metals visible under fluoroscopy generally result in beam hardeningartifacts that preclude the usefulness of computed tomography imagingfor medical purposes. Visualization agents for computed tomography arebarium sulfate and iodine-containing molecules. Barium sulfateconcentrations that can render the particles visible using fluoroscopicand computed tomography imaging range from about 30% w/w to about 60%w/w, about 30% w/w to about 50% w/w, about 30% w/w to about 40% w/w,about 40% w/w to about 50% w/w, about 40% w/w to about 60% w/w, or about45% w/w to about 60% w/w of the prepolymer solution used to form theparticles.

Iodine concentrations that can render the particles visible usingfluoroscopy and/or computed tomography range from about 80 mg to about500 mg of the prepolymer solution used to form the particles.

Visualization of the particles under magnetic resonance imaging can beimparted by the incorporation of solid particles of superparamagneticiron oxide or gadolinium molecules polymerized into the particlestructure. A visualization agent for magnetic resonance issuperparamagnetic iron oxide with a particle size of about 10 microns.Concentrations of superparamagnetic iron oxide particles to render theparticles visible using magnetic resonance imaging range from about 0.1%to about 1% w/w of the prepolymer solution used to form the particles.

Methods of forming polymer particles can include reacting a prepolymersolution including the components included in the polymer particle, suchas but not limited to at least one monomer amenable to polymerization,at least one crosslinker, and at least one pharmaceutical agent.

Methods of forming hydrogel particles can include reacting a prepolymersolution including the components included in the polymer particle, suchas but not limited to at least one monomer amenable to polymerization,at least one crosslinker; and at least one pharmaceutical agent.

The prepolymer solution including the polymerizable components can bepolymerized by reduction-oxidation, radiation, heat, or any other methodknown in the art. Radiation cross-linking of the prepolymer solution canbe achieved with ultraviolet light or visible light with suitableinitiators or ionizing radiation (e.g. electron beam or gamma ray)without initiators. Cross-linking can be achieved by application ofheat, either by conventionally heating the solution using a heat sourcesuch as a heating well, or by application of infrared light to themonomer solution. The free radical polymerization of the monomer(s) andcrosslinker(s) can be used and can utilize an initiator to start thereaction. In one embodiment, the cross-linking method utilizesazobisisobutyronitrile (AIBN) or another water soluble AIBN derivative(2,2′-azobis(2-methylpropionamidine) dihydrochloride). Othercross-linking agents useful according to the present description includeN,N,N′,N′-tetramethylethylenediamine, ammonium persulfate, benzoylperoxides, and combinations thereof, including azobisisobutyronitriles.In one embodiment, the initiator is AIBN at a concentration range ofabout 2% to about 5% w/w of the prepolymer solution.

The prepolymer solution can be prepared by dissolving the monomer(s),crosslinker(s), and initiator(s) in a solvent. The particles can beprepared by emulsion polymerization. A non-solvent for the prepolymersolution, typically mineral oil when the monomer solvent is hydrophilic,and a surfactant are added to the reaction vessel. An overhead stirreris placed in the reaction vessel. The reaction vessel is then sealed,and sparged with argon to remove any entrapped oxygen. The initiatorcomponent is added to the reaction vessel and stirring commenced.Additional initiator is added to the polymerization solution and bothare then added to the reaction vessel, where the stirring suspendsdroplets of the prepolymer solution in the mineral oil.

The rate of stirring can affect particle size, with faster stirringproducing smaller particles. Stirring rates can be about 100 rpm, about200 rpm, about 300 rpm, about 400 rpm, about 500 rpm, about 600 rpm,about 700 rpm, about 800 rpm, about 900 rpm, about 1,000 rpm, about1,100 rpm, about 1,200 rpm, about 1,300 rpm, between about 200 rpm andabout 1,200 rpm, between about 400 rpm and about 1,000 rpm, at leastabout 100 rpm, at least about 200 rpm, at most about 1,300 rpm, or atmost about 1,200 rpm to produce particles with desired diameters.

The particles can have diameters of about 10 μm, about 20 μm, about 30μm, about 40 μm, about 50 μm, about 60 μm, about 75 μm, about 100 μm,about 200 μm, about 300 μm, about 400 μm, about 500 μm, about 600 μm,about 700 μm, about 800 μm, about 900 μm, about 1,000 μm, about 1,100μm, about 1,200 μm, about 1,300 μm, about 1,400 μm, about 1,500 μm,about 1,600 μm, between about 50 μm and about 1,500 μm, between about100 μm and about 1,000 μm, between about 75 μm and about 1,200 μm, atleast about 50 μm, at least about 80 μm, at most about 1,500 μm, or atmost about 1,200 μm. In some embodiments, the diameter can be betweenabout 40 μm and about 1,200 μm, between about 40 μm and about 60 μm, orbetween about 75 μm and about 1,200 μm. In some embodiments, theparticles can be referred to as microspheres or microparticles.

In some embodiments, the particles described herein can have a generallyor substantially spherical shape.

In some embodiments, the polymer particles can retain their diameterseven after injection through a catheter or other delivery device. Inother words, the polymer particles may not fall apart or otherwisefracture during delivery. In some embodiments, the polymer particles canretain about 99%, about 98%, about 97%, about 96%, about 95%, about 90%,greater than about 99%, greater than about 98%, greater than about 97%,greater than about 96%, greater than about 95%, greater than about 90%,or between about 90% and about 100% of their diameter after delivery.

The particles can also have a characteristic circularity or have arelative shape that is substantially circular. This characteristicdescribes or defines the form of a region on the basis of itscircularity. Particles as described herein can have a fraction ofcircularity of about 0.8, 0.9, 0.95, 0.96, 0.97, 0.98, 0.99, greaterthan about 0.8, greater than about 0.9, or greater than about 0.95. Inone embodiment, the circularity of the particles is greater than about0.9.

The particles can retain their circularity even after injection througha catheter or other delivery device. In some embodiments, the particlescan retain about 99%, about 98%, about 97%, about 96%, about 95%, about90%, greater than about 99%, greater than about 98%, greater than about97%, greater than about 96%, greater than about 95%, greater than about90%, or between about 90% and about 100% of their circularity afterdelivery.

Polymerization can be allowed to proceed as long as necessary to produceparticles with desired resiliency. Polymerization can be allowed toproceed for about 1 hr, about 2 hr, about 3 hr, about 4 hr, about 5 hr,about 6 hr, about 7 hr, about 8 hr, about 9 hr, about 10 hr, about 11hr, about 12 hr, about 18 hr, about 24 hr, about 48 hr, about 72 hr,about 96 hr, between about 1 hr and about 12 hr, between about 1 hr andabout 6 hr, between about 4 hr and about 12 hr, between about 6 hr andabout 24 hr, between about 1 hr and about 96 hr, between about 12 hr andabout 72 hr, or at least about 6 hours.

Polymerization can be run at a temperature to produce particles withdesired resiliency and/or reaction time. Polymerization can be run at atemperature of about 10° C., about 20° C., about 30° C., about 40° C.,about 50° C., about 60° C., about 70° C., about 80° C., about 90° C.,about 100° C., between about 10° C. and about 100° C., between about 10°C. and about 30° C., at least about 20° C., at most about 100° C., or atabout room temperature. In one embodiment, polymerization occurs at roomtemperature.

In one embodiment, polymerization occurs overnight at room temperature.

After polymerization is complete, the particles can be washed to removeany solute, mineral oil, unreacted monomer(s), and unbound oligomers.Any solvent may be utilized, but care should be taken if aqueoussolutions are used to wash particles with linkages susceptible tohydrolysis. In some embodiments, washing solutions can include hexanes,dimethylformamide, acetone, alcohols, water with surfactant, water,saline, buffered saline, and saline and a surfactant.

Optionally, the washed particles can then be dyed to permitvisualization before injection into a microcatheter during preparationby the physician. A dye bath is made by dissolving sodium carbonate andthe desired dye in water. Any of the dyes from the family of reactivedyes which bond covalently to the particle can be used. Dyes can includereactive blue 21, reactive orange 78, reactive yellow 15, reactive blueNo. 19 reactive blue No. 4, C.I. reactive red 11, C.I. reactive yellow86, C.I. reactive blue 163, C.I. reactive red 180, C.I. reactive black5, C.I. reactive orange 78, C.I. reactive yellow 15, C.I. reactive blueNo. 19, C.I. reactive blue 21, any of the color additives approved foruse by the FDA part 73, subpart D, or any dye that will irreversiblybond to the particles. Particles can be added to the dye bath andstirred.

If the herein described particle does not adequately bind any of thereactive dyes described above, a monomer containing an amine can beadded to the monomer solution in an amount to achieve the desiredcoloration. Even if the particle does adequately bind the reactive dyesdescribed above, a monomer containing an amine can be added to themonomer solution. Examples of suitable amine containing monomers includeaminopropyl methacrylate, aminoethyl methacrylate, aminopropyl acrylate,aminoethyl acrylate, derivatives thereof, combinations thereof, andsalts thereof. In some embodiments, concentrations of the aminecontaining monomers in the final product can be less than or equal toabout 1% w/w.

After the dying process, any unbound dye is removed through copiouswashing. After dying and additional washing, the particles can bepackaged into vials or syringes, and sterilized.

The particles described herein can be sterilized without substantiallydegrading the polymer. After sterilization, at least about 50%, about60%, about 70%, about 80%, about 90%, about 95% about 99% or about 100%of the polymer can remain intact. In one embodiment, the sterilizationmethod can be autoclaving and can be utilized before administration.

The particles can be used to treat a mammal in need. Mammals caninclude, but are not limited to, humans, horses, camels, dogs, cats,cows, bears, rodents, oxen, bison, buffalo, caribou, moose, deer, elk,sheep, goats, pigs, rabbits, pouched mammals, primates, carnivores, orthe like.

The polymers can be used to fill aneurysms, provide an embolus, fillvessel malformations, fill biological voids, provide pharmaceuticalagents at a particular site, provide treatment to a surgical or injurysite, or the like. The methods can include administering to the vessel aplurality of particles as described herein. In some embodiments,hydrogel particles can be formed that swell once delivered or oncesubjected to an appropriate condition.

The final particle preparation can be delivered to the site to beembolized via a catheter, microcatheter, needle, or similar deliverydevice. In some embodiments, a radiopaque contrast agent can bethoroughly mixed with the particles in a syringe and injected through acatheter or similar delivery device until blood flow is determined to beoccluded from the site by interventional imaging techniques.

The particles can be delivered to a diseased site, with or withoutcomplete cessation of blood flow. Upon delivery to the diseased site,pharmaceutical agents can be released from the particles.

In some embodiments, the particles can be configured for embolization ofhypervascularized tumors or arteriovenous malformations. In someembodiments, a patient can be selected that exhibits a hypervascularizedtumor and/or an arteriovenous malformation. A microcatheter can benavigated to the location of the tumor or malformation. Particles asdescribed herein can be injected into that site to stabilize it therebytreating the patient's condition.

In other embodiments, the particles can be injected through a needle toa treatment site(s).

In some embodiments, it may be desirable for the particles to degradeover time. In other words, the particles can be degradable and/orbiodegradable. In such embodiments, the particles can degrade to lessthan about 40%, about 30% about 20%, about 10%, about 5%, or about 1% oftheir initial size after about 2 days, 3 days, 5 days, about 2 weeks,about 1 month, about 2 months, about 6 months, about 9 months, about ayear, about 2 years, about 5 years, or about 10 years. In oneembodiment, the particles can be substantially degraded in less thanabout 1 month. In another embodiment, the particles can be substantiallydegraded in less than about 6 months.

In some embodiments, degradability can be accelerated with anappropriate and/or adequate enzyme. In some embodiments, the particlescan be injected along with an enzyme that can accelerate the degradationof the particles. In other embodiments, an enzyme can be delivered tothe site of the implanted particles at a remote time and acceleratedegradation at that time.

In some embodiments, the greater the percentage of a crosslinker in thefinal particles, the longer degradation takes. Additionally, the largerthe particle diameter, the longer the degradation. Thus, the particleswith the longest degradation time are those that have the largestconcentration of crosslinker and the largest diameter. These twoproperties can be varied to tailor degradation time as needed.

The particles described herein can be compressible yet durable enoughnot to break apart or fragment. Substantially no change in circularityor diameter of particles occurs during delivery through a microcatheter.In other words, after delivery through a microcatheter, the polymerparticles described herein remain greater than about 60%, about 70%about 80%, about 90%, about 95%, about 99% or about 100% intact afterdelivery.

Further, in some embodiments, the particles can stick to the tissueand/or remain in place through friction with the tissues. In otherembodiments, the particles can act as a plug in a vessel held in placeby the flow and pressure of the blood itself. In still otherembodiments, the particles can be cohesive enough to stick to oneanother to aid in agglomerating particles at a particular site ofaction.

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and a polymerizable anticancer drug or aderivative thereof, crosslinked with

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and a polymerizable anticancer drug or aderivative thereof, crosslinked with

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and a polymerizable anticancer drug or aderivative thereof, crosslinked with

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and a polymerizable anticancer drug or aderivative thereof, crosslinked with

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and a polymerizable anticancer drug or aderivative thereof, crosslinked with

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and PPA1 or a derivative thereof, crosslinkedwith

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and PPA1 or a derivative thereof, crosslinkedwith

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and PPA1 or a derivative thereof, crosslinkedwith

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and PPA1 or a derivative thereof, crosslinkedwith

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and PPA1 or a derivative thereof, crosslinkedwith

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and PPA2 or a derivative thereof, crosslinkedwith

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and PPA2 or a derivative thereof, crosslinkedwith

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and PPA2 or a derivative thereof, crosslinkedwith

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and PPA2 or a derivative thereof, crosslinkedwith

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and PPA2 or a derivative thereof, crosslinkedwith

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and PPA3 or a derivative thereof, crosslinkedwith

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and PPA3 or a derivative thereof, crosslinkedwith

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and PPA3 or a derivative thereof, crosslinkedwith

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and PPA3 or a derivative thereof, crosslinkedwith

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and PPA3 or a derivative thereof, crosslinkedwith

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and PPA4 or a derivative thereof, crosslinkedwith

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and PPA4 or a derivative thereof, crosslinkedwith

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and PPA4 or a derivative thereof, crosslinkedwith

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and PPA4 or a derivative thereof, crosslinkedwith

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and PPA4 or a derivative thereof, crosslinkedwith

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and PPA5 or a derivative thereof, crosslinkedwith

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and PPA5 or a derivative thereof, crosslinkedwith

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and PPA5 or a derivative thereof, crosslinkedwith

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and PPA5 or a derivative thereof, crosslinkedwith

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and PPA5 or a derivative thereof, crosslinkedwith

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and PPA6 or a derivative thereof, crosslinkedwith

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and PPA6 or a derivative thereof, crosslinkedwith

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and PPA6 or a derivative thereof, crosslinkedwith

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and PPA6 or a derivative thereof, crosslinkedwith

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and PPA6 or a derivative thereof, crosslinkedwith

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and PPA7 or a derivative thereof, crosslinkedwith

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and PPA7 or a derivative thereof, crosslinkedwith

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and PPA7 or a derivative thereof, crosslinkedwith

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and PPA7 or a derivative thereof, crosslinkedwith

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and PPA7 or a derivative thereof, crosslinkedwith

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and PPA8 or a derivative thereof, crosslinkedwith

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and PPA8 or a derivative thereof, crosslinkedwith

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and PPA8 or a derivative thereof, crosslinkedwith

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and PPA8 or a derivative thereof, crosslinkedwith

In some embodiments, the particles can include dimethyl acrylamide,glycerol monomethacrylate, and PPA8 or a derivative thereof, crosslinkedwith

When using the particles to deliver a pharmaceutical agent, thepharmaceutical agent can be delivered over time once delivered. In someembodiments, the pharmaceutical agent/drug can be eluted from theparticles at a rate of about 3% to about 5% of the loaded pharmaceuticalagent per day. In some embodiments, the total amount of pharmaceuticalagent eluted during the first 8 days can be greater than about 30% ofthe loaded pharmaceutical agent. In some embodiments, the total amountof pharmaceutical agent eluted during the first 8 days can be less thanabout 40% of the loaded pharmaceutical agent.

In some embodiments, the pharmaceutical agent can have its highestsystemic concentration at about 2 hrs, about 3 hrs, about 4 hrs, about 5hrs, about 6 hrs, about 7 hrs, about 8 hrs, at least about 2 hrs, atleast about 3 hrs, or at least about 4 hrs after delivery. In someembodiments, the pharmaceutical agent can be substantially eluted fromthe polymer particles about 4 days, about 5 days, about 6 days, about 7days, about 8 days, at least about 2 days, at least about 3 days, atleast about 4 days, at most about 8 days, at most about 9 days, or atmost about 10 days after delivery.

Example 1 Preparation of a Polymerizable Pharmaceutical Agent

Synthesis of 2: To a 200 mL amber jar fitted with a stir bar was addedsolid oxaliplatin (1, 8 g, 20.2 mmol). To this solid was added 30%hydrogen peroxide (11.5 mL, 101 mmol) and glacial acetic acid (97 mL,1.70 mol) sequentially. The bottle was wrapped in aluminum foil and leftin the darkness for 48 hours. This step of the synthesis was also runfor 24 hours instead of 48. After that the solution was transferred intoa 500 mL recovery flask. The solvent was removed by rotary evaporationto leave a residual syrup. Methanol (MeOH) (10 mL) and diethyl ether(Et₂O) (100 mL) were added to this residue, which was stirred overnightto induce precipitation. The solid precipitate was collected byfiltration and dried under vacuum overnight. The product is a lightyellowish solid (8.6909 g). (Zhang, Jenny Z. et al, Chemistry—A EuropeanJournal, 2013, 19, 1672-1676.)

Synthesis of 5: To an oven-dried 50 mL Schleck flask fitted with a stirbar was added (methacryloyloxy)acetic acid (3, 1.99 g, 13.78 mmol) andanhydrous tetrahydrofuran (THF) (34.4 mL) under argon. The flask wascooled in an ice bath. To the cooled flask was addeddicyclohexylcarbodiimide (DCC) (2.84 g, 13.78 mmol). The solution wasstirred for 1 hour while white precipitate began to form. Then a Schleckfiltration was performed to remove the precipitate, and the filtrate wascollected into a 100 mL oven-dried 3-neck round bottom flask fitted witha stir bar. Mono-acetoxy mono-hydroxy oxaliplatin (2, 5 g, 10.6 mmol)was added to the flask, which was then wrapped in aluminum foil. Ifnecessary, another aliquot of the anhydride can be added to drive thereaction to completion. The reaction was stirred for 17 hours. To workup the reaction, about 160 mL MeOH was added to the reaction. Theundissolved solid was separated by filtration. The filtrate wasconcentrated on a rotary evaporator to a residue, which was laterseparated on a flash column (silica, MeOH/dichloromethane (DCM)) toyield 5 (0.97 g) as a slightly greenish solid.

Example 2 Preparation of a Polymerizable Pharmaceutical Agent

Synthesis of 7: To an oven-dried 1000 mL 3-neck round bottom flaskfitted with a stir bar was added SN-38 (6, 10 g, 25.5 mmol). Cannulatransferred DCM (489 mL) to the flask. Added pyridine (525.3 mmol, 42.3mL) and di-tert-butyl dicarbonate (Boc₂O) (42.3 mL, 33.2 mmol)sequentially to the flask. Stir overnight. To work up, transferred thereaction to a 1 L recovery flask and removed the solvent on a rotaryevaporator. Recrystallized the product from boiling isopropanol.Collected the solid by filtration and washed the filtrate with coldisopropanol. Blew dry the solid under argon overnight to yield theproduct as a light-yellow solid (11.82 g).

Synthesis of 8: To an oven-dried 250 mL 3-neck round bottom flask wasadded Boc-protected SN-38 (7, 2 g, 4.1 mmol). To this solid was addedDCM (82 mL), (methacryloyloxy)acetic acid (3, 590.9 mg, 4.1 mmol), and4-dimethylaminopyridine (DMAP) (500.9 mg, 4.1 mmol). The flask wascooled in an ice bath before N,N′-diisopropylcarbodiimide (DIC) (642 μL,4.1 mmol) was added. The reaction was stirred in an ice bath for 30 min.After that, it was stirred under room temperature for 4 hours. To workup the reaction, the reaction mixture was poured over of 0.5% NaHCO₃ (10mL). The organic fraction was collected and washed with 0.1 M HCl (10mL) before being dried over Na₂SO₄. Then the solvent was removed on arotary evaporator to give the crude product, which was separated on aflash column (silica, acetone/DCM) to give the product as a yellow solid(313.4 mg).

Synthesis of 9: To an oven-dried round bottom flask fitted with a stirbar was added the 8 (1.61 g, 2.6 mmol). To the solid was added anhydrousDCM (26 mL) and trifluoroacetic acid (TFA) (26 mL) sequentially. Thesolution was stirred at room temperature for 1 hour. Then the solutionwas transferred to a recovery flask and the solvent was removed on arotary evaporator. The residue was separated by flash chromatography(silica, DCM/acetone) to yield the product as a light yellow solid (968mg, 72%).

Example 3 Preparation of a Particle Containing a PolymerizablePharmaceutical Agent

Mineral oil (300 mL) was added to a sealed jacketed-reaction vesselequipped with an overhead stirring element and a heating elementmaintained at 85° C. The vessel was sparged with argon for 1-2 hourswhile mixing. A prepolymer solution was prepared by dissolving 0.96 gacrylamide, 0.64 g hydroxypropyl acrylate, 0.01 gN,N′-methylenebisacrylamide, 0.12 g of azobisisobutyronitrile and 0.40 gof an Oxaliplatin monomer (1), prepared as in Example 1, in 2.0 g ofdimethylformamide. Once dissolved, the solution was sparged with argonfor 5 min. Azobisisobutyronitrile (0.5 g) was added to the reactionvessel and overhead stirring increased to 400 rpm. After approximately10 min, an aliquot of SPAN®80 (1 mL) was added to the mineral oil andallowed to mix. The prepolymer solution was added to the reaction vesseland the resulting suspension was allowed to polymerize for an hourbefore the heat was turned off. The resulting solution was mixed in thereaction vessel overnight.

Example 4 Preparation of a Particle Containing a PolymerizablePharmaceutical Agent

Mineral oil (300 mL) was added to a sealed jacketed-reaction vesselequipped with an overhead stirring element and a heating elementmaintained at 85° C. The vessel was sparged with argon for 1-2 hourswhile mixing. A prepolymer solution was prepared by dissolving 0.6 gacrylamide, 0.4 g hydroxypropyl acrylate, 0.013 gN,N′-methylenebisacrylamide, 0.075 g of azobisisobutyronitrile and 0.25g of an SN-38 monomer (2), prepared as in Example 2, in 1.25 g ofdimethylformamide. Once dissolved, the solution was sparged with argonfor 5 min. Azobisisobutyronitrile (0.5 g) was added to the reactionvessel and overhead stirring increased to 400 rpm. After approximately10 min, an aliquot of SPAN®80 (1 mL) was added to the mineral oil andallowed to mix. The prepolymer solution was added to the reaction vesseland the resulting suspension was allowed to polymerize for an hourbefore the heat was turned off. The resulting solution was mixed in thereaction vessel overnight.

Example 5 Purification of Particles

After the polymerization was complete, the mineral oil was decanted fromthe reaction vessel and the polymer particles were washed with hexane toremove leftover mineral oil. The particles were separated from thesolution and washed with an aliquot of dimethylformamide. Washes withfresh portions of solution were repeated for hexane anddimethylformamide. A final wash was done for 2 hours indimethylformamide.

The particles were separated by sizes using a sieving process. Sieveswere stacked from the largest size (on top) to the smallest size (onbottom). A sieve shaker was utilized to aid in the sieving process. Theparticles were placed on the top sieve along with an aliquot ofdimethylformamide. Once all the particles had been sorted, they werecollected and placed in bottles according to their size.

After sieving, the particles were dehydrated to extend their shelf life.Under stirring, the particles were placed in a graded series ofacetone/dimethylformamide mixtures. For at least 4 hours, the particleswere suspended in solvent mixtures ranging from 75% solvent to 100%solvent. Subsequently, the particles were lyophilized, packaged, andsterilized.

Example 6 In Vitro Elution of Pharmaceutical Agents from Particles

Into a 10 mL plastic syringe, 100 mg of dry SN-38 preloaded particleswere added. The particles were suspended in 6 mL of phosphate bufferedsaline (PBS) and placed at 37° C. oven. At 15 and 30 minutes, 1, 2, 3,4, 5, and 6 hours, a clean 5 μm filter needle was attached and theextract solution was expelled as much as possible. The particles werere-suspended with another 6 mL of PBS and placed back at 37° C. Afterthe 24 hour sample was collected, the particles were transferred to a 60mL plastic syringe, suspended in 12 mL of PBS and placed at 37° C. oven.After the 48 hour sample was collected, the particles were suspended in60 mL of PBS and continued to be suspended in 60 mL of PBS for futuretime points. The sampling was continued daily for a total of 8 days. ThepH of the sample was adjusted to 3 by spiking 1 mL of sample with 10 μLof 0.1 M HCl before chromatographic analysis.

The concentration of SN-38 in each sample was determined using anAgilent 1260 Infinity HPLC system. The chromatographic analysis wasperformed in a gradient mode with an Agilent Poroshell 120 C18 column(4.6 mm×50 mm, 2.7 μm). The mobile phases delivered at 1 mL/min,consisted of buffer A: acetonitrile and buffer B: 10 mM KH₂PO₄, pH 3 and5% acetonitrile. The chromatographic gradient was 30% buffer A from0.0-2.0 min, 30-70% from 2.0-2.1 min, 70% from 2.1-4.9 min and 70-30%from 4.9-5.0 min with a post time of 3 mins. The injection volume was 5μL and the wavelength of the ultraviolet detector was 223 nm. Thecalibration curve was prepared from 0.5 to 100 ppm of SN-38. The amountof SN-38 released and relative percentage were calculated from theconcentration data.

Due to the poor solubility of SN-38 in water and formation of yellowprecipitate in the extract solution, volume of extract solution wasadjusted from 6 mL to 60 mL for 24 hour samples. The kinetics of SN-38elution from the preloaded particles is illustrated in FIG. 1. Thetheoretical amount of SN-38 tethered on the particles is 15 mg for 100mg of particles assuming no loss of the drug during the preparation ofthe particles. Upon immersion in PBS, SN-38 was eluted slowly over aperiod of time. On day 8, there was approximately 3% of SN-38 eluted.The elution curve obtained is fairly close to a linear line over theperiod of 8 days with a steady daily release between 3-5% of loadedSN-38 indicating controlled release of SN-38 is achieved with thepreloaded particles. The total amount of SN-38 eluted during the first 8days was 34% of the theoretical amount.

Example 7 In Vivo Elution of Pharmaceutical Agents from Particles

Blood samples were obtained to determine the systemic concentration ofSN-38 before embolization as well as 20, 40, 60, 120 and 180 minutespost-embolization. An additional blood sample was collected atsacrifice, which was at day 6. Plasma was prepared by centrifugation andthe samples were frozen at −80° C. until analysis.

Quantitation was done via liquid chromatography-tandem mass spectrometry(LC/MS/MS) using an Agilent 1260 Infinity HPLC system coupled withABSciex 4000 Q Trap LC/MS/MS system. Chromatographic separation wasperformed using an Agilent Poroshell 120 C18 column (4.6 mm×50 mm, 2.7μm) at 25° C. and mobile phases consisting of A: 0.1% formic acid inacetonitrile and B: 0.1% formic acid in water. At a flow rate of 1.0mL/min, the chromatographic gradient was 27% buffer A from 0.0-0.3 min,27-52% from 0.3-2.5 min, 52-80% from 2.5-2.6 min, 80% from 2.6-2.7 min,80-27% from 2.7-2.8 min, 27% from 2.9-4.0 min. The plasma samples wereprecipitated with 3 fold excess (v/v) of acetonitrile containing 50 ppbof the internal standard, camptothecin. After being vortexed andcentrifuged at 13,000 rpm at 4° C. for 10 minutes, 200 μL of thesupernatant of each sample was diluted with 600 μL of 0.1% formic acidin water. Injection of 100 μL of the diluted sample was performed. Thecalibration curve was prepared by spiking blank plasma to a range from2.5-500 ppb for SN-38. The systemic concentration of SN-38 in plasmaover time is illustrated in FIG. 2. At each time point, theconcentration of SN-38 was lower than the lower limit of quantitation.The highest systemic concentration was at 3 hrs post embolization and atday 6 the systemic concentration remained similar to 2 hrs postembolization.

Example 8 In Vivo Elution of Pharmaceutical Agents from Particles

Blood samples were obtained to determine the systemic concentration ofoxaliplatin before embolization as well as 20, 40, 60, 120 and 180minutes post-embolization. An additional blood sample was collected atsacrifice, which was at day 6 or day 7. Plasma was prepared bycentrifugation and the samples were frozen at −80° C. until analysis.

Quantitation was done via LC/MS/MS using an Agilent 1260 Infinity HPLCsystem coupled with ABSciex 4000 Q Trap LC/MS/MS system. Chromatographicseparation was performed using an Agilent Poroshell 120 C18 column (4.6mm×50 mm, 2.7 μm) at 50° C. and mobile phase consisting of A: 0.1%formic acid in acetonitrile and B: 0.1% formic acid in water. At a flowrate of 500 μL/min, the chromatographic gradient was 0% buffer A from0.0-2.5 min, 0-90% from 2.5-2.6 min, 90% from 2.6-4.1 min, 90-0% from4.1-4.2 min, and 0% from 4.2-10.0 min. The divert valve was open from1.4-2.7 min and 3.4-4.6 min. The plasma samples were purified byultracentrifugation first and then solid phase extraction. Plasmasample, 500 μL, was loaded onto a 30K Nanosep Centrifuge Device andcentrifuged to collect the plasma ultra-filtrate. The centrifugation wasperformed at 4° C., starting at 8,000 rcf for 30 mins, 9,000 rcf for 30mins, and 10,000 rcf for 15 mins with an increment of 1,000 rcf every 15mins until 13,000 rcf for 2 hrs and 15 mins. The collected plasmaultra-filtrate was diluted with 1:1 (v/v) ratio of acetonitrilecontaining 500 ppb of the internal standard, carboplatin. The mixture,600 μL, was loaded onto a 1 mL HybridSPE-Phospholipid cartridge, whichwas placed in a 15 mL conical centrifuge tube and centrifuged at 4° C.at 1,000 rcf for 5 mins and then 4,000 rcf for 5 mins. The samplecollected in the centrifuge tube was then transferred to an HPLC vialfor analysis. Injection of 50 μL of the sample was performed. Thecalibration curve was prepared by spiking the blank plasmaultra-filtrate to a range from 5-2000 ppb. The systemic concentration ofoxalipatin in plasma over time is illustrated in FIG. 3. At each timepoint, the concentration of oxaliplatin was lower than the lower limitof quantitation. For one sample pig, the highest systemic concentrationwas at 3 hrs post embolization and at day 6 the systemic concentrationwas close to pre-embolization.

Example 9 Biodegradable Crosslinker

Synthesis of 10: To 2,2′-(ethylenedioxy)bis(ethylamine) (10 g, 67.6mnol) was added glycidyl methacrylate (10 g, 70.4 mmol) and silica gel(3 g, Aldrich 645524, 60 Å, 200-425 mesh) with good stirring. Afterstirring for 1 hr, another aliquot of glycidyl methacrylate (9 g, 63.4mmol) was added and the suspension was stirred for an additional 1.5 hr.The reaction mixture was diluted with chloroform (200 mL) and filteredthrough a 600 mL fritted glass Buchner funnel of medium porosity, toremove the silica gel. LC-MS analysis of the resultant chloroformsolution showed almost no mono-glycidyl amino alcohol and mostlybis-glycidyl amino alcohol, 10 at (M+H)⁺ 433.2 and was concentrated toabout 50 g in vacuo. The resultant heavy syrup was diluted to 100 mLwith acetonitrile and stored at −80° C.

Example 10 Biodegradable Crosslinker

Synthesis of dithioester 11: An oven-dried 250 mL 3-neck round bottomflask was fitted with a stir bar and a 100 mL addition funnel. To thisflask was added 3,6-dioxaoctane-1,8-dithiol (20.0 g, 110 mmol), THF (100mL), and diisopropylamine (DIEA) (15.8 mL, 90.0 mmol) sequentially. Theflask was cooled in 0° C. ice bath. Then succinyl chloride (5.0 mL, 45.0mL) and THF (40 mL) were added to the funnel. The succinyl chloridesolution was added dropwise into the reaction mixture, which was stirredovernight. To work up, the brown solution with white precipitate wasfiltered over a medium-porosity glass fritted funnel. The filtrate waspassed through a silica gel plug. The filtrate was concentrated underreduced pressure to give a brown syrup, which was first dissolved in 100mL DCM. Using gentle swirling, the DCM fraction was washed with 0.1 MNaHCO₃ (100 mL) and saturated NaCl solution (100 mL). The DCM fractionwas dried over Na₂SO₄, and the solvent was removed under reducedpressure to give a red liquid (29.65 g). The liquid can be decolorizedwith activated charcoal, before being separated on a flash column togive 11 as an oily liquid (3.93 g).

Synthesis of tetrathioester 12: A 250 mL 3-neck round bottom flaskfitted with a stir bar was dried in the oven. To this round bottom flaskwas added 11 (2.00 g, 4.48 mmol). DCM (144 mL) was cannula transferredto the flask with stirring. Then methacrylic acid (1.00 g, 11.6 mmol)and DMAP (110 mg, 0.896 mmol) were added to the flask. The reactionflask was cooled in an ice bath first and then added1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDCl.HCl)(2.57 g, 13.4 mmol) portion-wise. The reaction was stirred for 3 hoursafter the addition. To work up, the reaction was sequentially washedwith 1 M NaHCO₃ (150 mL) and saturated NaCl (150 mL). The organicfraction was dried over MgSO₄ and passed through a silica gel plug. Thesolvent was removed under reduced pressure to yield the crude product,which was separated on a flash column (normal phase, ethylacetate/hexanes) to give the product as a clear liquid (1.5 g, 58%).

Example 11 Biodegradable Crosslinker

Synthesis of 2-(methacryloxy)ethyl oxalyl monochloride, 13: Anoven-dried 100 mL three-neck round bottom flask was purged under argon.The flask was fitted with a stir bar and an addition funnel. To theflask was added oxalyl chloride (20 g, 158 mmol) and anhydrous DCM (15mL) sequentially. To the addition funnel added 2-hydroxyethylmethacrylate (HEMA) (16 g, 123 mmol). The flask was cooled in an icebath and added HEMA dropwise to the reaction. After the addition wasfinished, the flask was left stirring in the ice bath for 1 hour. Theflask was pulled out of the ice bath and kept stirring for 1 hour. Towork up, removed the DCM and oxalyl chloride on a rotary evaporator.Avoid moisture from here on. The product is a greenish liquid. It doesnot move on a silica TLC plate and has strong UV absorption. (U.S. Pat.No. 5,395,736 A 19950307)

Synthesis of 14: An oven-dried 50 mL three-neck round bottom flask waspurged under argon. Added 2-(methacryloxy)ethyl oxalyl monochloride (13,12 g, 54.4 mmol) and anhydrous DCM (25.4 mL) to the reaction flask.Added pyridine (5.08 g, 64.2 mmol) and 1,3-propanediol (1.88 g, 24.7mmol) sequentially to the flask. To work up, began with filtering offthe white precipitate. Washed the filtrate with 5% citric acid (50mL×2). Washed the DCM fraction with saturated sodium chloride (50 mL)and dry over Na₂SO₄. The solvent was removed under reduced pressure togive the crude product as a thick yellowish liquid. The product wasobtained after a flash column separation (normal phase, ethylacetate/hexanes) as a clear liquid.

Example 12 Biodegradable Crosslinker

Synthesis of 15: In a 50 mL round bottom flask, dissolved6-aminohexanoic acid (8.45 g, 64.6 mmol) and NaOH (2.6 g, 65 mmol) inddH₂O (13 mL). The flask was cooled in an ice bath. To this solution wasadded methacryloyl chloride (6.26 mL, 64 mmol) dropwise and then stirredfor two hours. To work up, washed the reaction with DCM (12.5 mL). Keptthe aqueous fraction and adjusted the pH of the aqueous layer to 2.0with 1 M HCl. Extracted the aqueous layer with ethyl acetate (30 mL×3).Combined the organic fraction and dried over Na₂SO₄. Removed the solventunder reduced pressure. The crude product was crystallized with ethylacetate and hexanes to give the product as clear crystals (4.65 g,36.5%).

Synthesis of 16: A three-neck round bottom flask was purged under argon.Added 6-(methacryloylamino)hexanoic acid (2.5 g, 12.6 mmol) and DCM (50mL) to the flask. Added thionyl chloride (4.50 g, 37.8 mmol) dropwise tothe solution with stirring. Stirred for one hour. Removed the solvent,thionyl chloride, and the byproduct under reduced pressure to yield theproduct as a yellowish liquid.

Synthesis of 17: A 100 mL round bottom flask fitted with a stir bar waspurged under argon. To this flask was added sodium azide (0.774 g, 11.91mmol), Adogen 464 (0.011 mL), and ddH₂O (25.1 mL) sequentially. Theflask was cooled in ice bath. To this aqueous solution was added toluene(25.1 mL) and 6-[(2-methyl-1-oxo-2-propen-1-yl)amino]hexanoyl chloride(16, 2.47 g, 11.3 mmol) sequentially. Stirred for 45 minutes and removedthe aqueous layer thereafter. Wash the organic fraction with ddH₂O (10mL). Then dried the organic fraction over Na₂SO₄ and decolorized withcharcoal. Removed the Na₂SO₄ and charcoal with filtration. Removed thesolvent under reduced pressure to yield the product as a clear liquid(0.73 g).

Synthesis of Allyl Ester 18: To a 500 mL three-neck round bottom flaskfitted with a stir bar was added 4-hydroxybenzenepropionic acid (50 g,0.3 mol) and allyl alcohol (204 mL, 3 mol). To this mixture was addedsulfuric acid (0.6 g, 6 mmol). The reaction was stirred at 95° C.overnight. The reaction was cooled to room temperature and poured overddH₂O (200 mL). The aqueous phase was extracted with dichloromethane(150 mL). The organic fraction was subsequently washed with ddH₂O (200mL), NaHCO₃ solution (200 mL, followed by 150 mL), and brine (200 mL).The organic fraction was dried over MgSO₄ and the solvent was removed ona rotary evaporator. The crude product was decolorized with charcoal andstabilized with phenothiazine (28 mg). The crude product was furtherpurified with flash chromatography (normal phase, hexanes/ethyl acetate)to yield the product as an oily liquid (43.8 g, 70.8%).

Synthesis of Carbamate Crosslinker 19: To an oven-dried three-neck roundbottom flask fitted with a stir bar was added phenothiazine (0.7 mg),N-(5-isocyanatopentyl)-2-methyl-2-propenamide (17, 730 mg, 4.31 mmol),toluene (5 mL), and trimethylamine (600 μL) to the flask. A solution of18 (740 mg, 3.59 mmol) in toluene (6 mL) was added. The solution wasplaced in an oil bath and refluxed overnight. The solvent was removed atthe end of the reaction to obtain the crude product, which was separatedon a flash column to yield the product as a white solid (470 mg).

Example 13 Biodegradable Crosslinker

Synthesis of Oxalate Diester 20: To a 100 mL round bottom flask with astir bar was added oxalic acid (5.4 g, 60 mmol),1-butyl-3-methylimidazolium bromide ([Bmim]Br) (18 g, 84 mmol) and4-methoxyphenol (120 mg, 0.97 mmol). The content was melted at 90° C.with stirring for 15 minutes. After adding glycidyl methacrylate (17.04g, 120 mmol), the reaction was stirred at 90° C. for 1 hour. Thin layerchromatography stain with 4-(4-nitrobenzyl)pyridine showed fullconsumption of the epoxide. The reaction mixture was suspended in 200 mLof ethyl acetate (EtOAc) and washed with water (100 mL×2), saturatedsodium bicarbonate (100 mL×2), and brine (100 mL). The organic phase wascollected and dried over sodium sulfate. The crude was dried undervacuum and purified with flash chromatography (DCM/EtOAc). Total of 12.7g of purified product was obtained as a clear liquid.

Example 14 Preparation of a Polymerizable Pharmaceutical Agent

Synthesis of 22: 3-aminopropyl methacrylamide hydrochloride (21) issuspended in a solution of proton sponge in anhydrous dichloromethane.This suspension is added dropwise to an ice-cold solution of diphosgenein anhydrous dichloromethane. After the reaction is over, the solvent isremoved under reduced pressure. The residue is re-dissolved indichloromethane and washed successively with 1N HCl and 1N NaOH. Theorganic fraction is stabilized with phenothiazine and dried over MgSO₄.The solvent is removed under reduced pressure to afford 22.

Synthesis of 23: To a suspension of SN-38 in anhydrous DMF was added 22,followed by triethylamine. The reaction can be driven to completion byoptional heating. Upon completion, the solvent is removed under reducedpressure. The residue can be purified by crystallization or flashchromatography.

Example 15 Preparation of Polymerizable Pharmaceutical Agent

Synthesis of 3-(4-Hydroxyphenyl)-propionic acid t-butyl ester (24): To asolution of 3-(4-Hydroxyphenyl)-propionic acid in dimethylformamide wascarefully added carbonyl diimidazole. The reaction mixture was stirredat 40° C. for 2 hours. DBU and t-butanol were then added and thereaction mixture was stirred at 65° C. for 2 days after which time TLCindicated that the starting material had been consumed. The reactionmixture was cooled to room temperature, water (40 mL) added and theproduct extracted with MTBE. The organic fraction was dried,concentrated under reduced pressure and the product isolated by flashcolumn chromatography to give the product as a colorless oil.

Synthesis of 2-methyl-acrylic acid 3-isocyanato-propyl amide (25): CDIis suspended in dry THF at room temperature. The suspension is cooled to17° C. After about 30 min stirring, APMA hydrochloride is added to themixture under cooling on ice portion-wise during while keeping thereaction temperature at 23° C. A yellow suspension was obtained. Afterabout 3 hours of stirring, the suspension is filtered. The filtrationwas stabilized with phenothiazine and concentrated to obtain2-methyl-acrylic acid 3-[(imidazole-1-carbonyl-amino]-propyl amide as aclear orange resin. 2-methyl-acrylic acid3-[(imidazole-1-carbonyl-amino]-propyl amide is dissolved in anhydrouschloroform at room temperature. The solution is then diluted withtoluene. To this suspension is added dry hydrochloride gas within about30 min, while cooling. After a clear liquid phase is formed, stir thisreaction for another hour. Then distilled chloroform from this reactionmixture while heating it to 69-74° C. Then the reaction will be kept at91-92° C. for 1 hour. Then stir for 1 hour at room temperature. Thetoluene phase is collected and concentrated in darkness. Distill theresidue at 48° C. to obtain the final product as a colorless oil. (Togenerate dry hydrogen chloride gas, slowly drip concentrated hydrogenchloride solution from an addition funnel into anhydrous calciumchloride. The gas evolved can be directed bubbled into the reaction.)

To synthesize 26, react 24 and 25 in the presence of triethyl amineusing toluene as a solvent. The reaction can be refluxed overnight ifnecessary.

De-protection of 26: 26 is stirred in a 50/50 v/v mixture of TFA and DCMat room temperature for one hour. The solvent and TFA is then removed ona rotovap. The residue will be purified on a flash chromatography.Alternatively, it can be de-protected in a mixture of CeCl₃.7H₂O/NaI inacetonitrile. Work up include dilution with ether and acidification withHCl. The HCl phase will then be extracted with diethyl ether. The etherphases are combined and dried over Na₂SO₄. The concentrated ether phaseis purified by flash chromatography to afford 27.

Synthesis of 28: 27 can be prepared via the anhydride method or directcoupling method. To perform the direct coupling method, 27 is dissolvedin anhydrous THF under inert atmosphere. To this solution is added DMAPand the oxaliplatin complex 2. The flask is cooled in ice bath. Then DCCwill be added portion-wise. The reaction is allowed to stir overnightbefore being filtered to obtain the filtrate. The filtrate isconcentrated and separated on a normal phase column to obtain 28. Theanhydride method is similar to what was described in Example 1.

Unless otherwise indicated, all numbers expressing quantities ofingredients, properties such as molecular weight, reaction conditions,and so forth used in the specification and claims are to be understoodas being modified in all instances by the term “about.” Accordingly,unless indicated to the contrary, the numerical parameters set forth inthe specification and attached claims are approximations that may varydepending upon the desired properties sought to be obtained by thepresent invention. At the very least, and not as an attempt to limit theapplication of the doctrine of equivalents to the scope of the claims,each numerical parameter should at least be construed in light of thenumber of reported significant digits and by applying ordinary roundingtechniques. Notwithstanding that the numerical ranges and parameterssetting forth the broad scope of the invention are approximations, thenumerical values set forth in the specific examples are reported asprecisely as possible. Any numerical value, however, inherently containscertain errors necessarily resulting from the standard deviation foundin their respective testing measurements.

The terms “a,” “an,” “the” and similar referents used in the context ofdescribing the invention (especially in the context of the followingclaims) are to be construed to cover both the singular and the plural,unless otherwise indicated herein or clearly contradicted by context.Recitation of ranges of values herein is merely intended to serve as ashorthand method of referring individually to each separate valuefalling within the range. Unless otherwise indicated herein, eachindividual value is incorporated into the specification as if it wereindividually recited herein. All methods described herein can beperformed in any suitable order unless otherwise indicated herein orotherwise clearly contradicted by context. The use of any and allexamples, or exemplary language (e.g., “such as”) provided herein isintended merely to better illuminate the invention and does not pose alimitation on the scope of the invention otherwise claimed. No languagein the specification should be construed as indicating any non-claimedelement essential to the practice of the invention.

Groupings of alternative elements or embodiments of the inventiondisclosed herein are not to be construed as limitations. Each groupmember may be referred to and claimed individually or in any combinationwith other members of the group or other elements found herein. It isanticipated that one or more members of a group may be included in, ordeleted from, a group for reasons of convenience and/or patentability.When any such inclusion or deletion occurs, the specification is deemedto contain the group as modified thus fulfilling the written descriptionof all Markush groups used in the appended claims.

Certain embodiments of this invention are described herein, includingthe best mode known to the inventors for carrying out the invention. Ofcourse, variations on these described embodiments will become apparentto those of ordinary skill in the art upon reading the foregoingdescription. The inventor expects skilled artisans to employ suchvariations as appropriate, and the inventors intend for the invention tobe practiced otherwise than specifically described herein. Accordingly,this invention includes all modifications and equivalents of the subjectmatter recited in the claims appended hereto as permitted by applicablelaw. Moreover, any combination of the above-described elements in allpossible variations thereof is encompassed by the invention unlessotherwise indicated herein or otherwise clearly contradicted by context.

Furthermore, numerous references have been made to patents and printedpublications throughout this specification. Each of the above-citedreferences and printed publications are individually incorporated hereinby reference in their entirety.

In closing, it is to be understood that the embodiments of the inventiondisclosed herein are illustrative of the principles of the presentinvention. Other modifications that may be employed are within the scopeof the invention. Thus, by way of example, but not of limitation,alternative configurations of the present invention may be utilized inaccordance with the teachings herein. Accordingly, the present inventionis not limited to that precisely as shown and described.

We claim:
 1. A method of forming a particle comprising: reacting aprepolymer solution including at least one monomer amenable topolymerization, at least one crosslinker, and at least one polymerizablepharmaceutical agent, and forming the particle, wherein the at least onepolymerizable pharmaceutical agent is chemically bonded to the particlewith a hydrolytically degradable linkage.
 2. The method of claim 1,wherein the particle is biostable.
 3. The method of claim 1, wherein theparticle is biodegradable.
 4. The method of claim 1, wherein the atleast one monomer amenable to polymerization includes glycerolmonomethacrylate, dimethyl acrylamide, or a combination thereof.
 5. Themethod of claim 1, wherein the polymerizable pharmaceutical agent has astructure


6. The method of claim 1, wherein the polymerizable pharmaceutical agenthas a structure

wherein n is 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12; p is 1, 2, 3,4, 5, 6, 7, 8, 9, 10, 11, or 12; R is N or NH; and R′ is H or CH₃. 7.The method of claim 6, wherein the polymerizable pharmaceutical agenthas a structure


8. The method of claim 1, wherein the polymerizable pharmaceutical agenthas a structure

wherein q is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12; X is O or NH; andX′ is H or CH₃.
 9. The method of claim 1, wherein the polymerizablepharmaceutical agent has a structure


10. The method of claim 1, wherein the crosslinker is


11. A method of treating a vessel comprising: administering to thevessel a plurality of particles wherein the particles are formed from aprepolymer solution including at least one monomer amenable topolymerization, at least one crosslinker, and at least one polymerizablepharmaceutical agent, wherein the at least one polymerizablepharmaceutical agent is chemically bonded to the particle with ahydrolytically degradable linkage.
 12. The method of claim 11, whereinthe particle is biostable.
 13. The method of claim 11, wherein theparticle is biodegradable.
 14. The method of claim 11, wherein the atleast one monomer amenable to polymerization includes glycerolmonomethacrylate, dimethyl acrylamide, or a combination thereof.
 15. Themethod of claim 11, wherein the polymerizable pharmaceutical agent has astructure


16. The method of claim 11, wherein the polymerizable pharmaceuticalagent has a structure

wherein n is 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12; p is 1, 2, 3,4, 5, 6, 7, 8, 9, 10, 11, or 12; R is N or NH; and R′ is H or CH₃. 17.The method of claim 16, wherein the polymerizable pharmaceutical agenthas a structure


18. The method of claim 11, wherein the polymerizable pharmaceuticalagent has a structure

wherein q is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12; X is O or NH; andX′ is H or CH₃.
 19. The method of claim 11, wherein the polymerizablepharmaceutical agent has a structure


20. The method of claim 11, wherein the crosslinker is